The present invention relates to a process for treating caramel colors and, more particularly, to a process for treating caramel colors to prepare caramel color concentrates.
Caramel colors are widely-used colorants which are prepared commercially from food grade nutritive carbohydrate sweeteners (glucose and fructose and/or polymers thereof, e.g., sugar, corn-syrup and starch hydrolyzates) by controlled heating of these materials to generate desired degrees of unsaturation, polymerization and color. For most food or beverage-grade applications, the preparation processes are augmented or catalyzed by the addition of ammonia, sulfite or combinations thereof. An identity scheme proposed by the International Technical Caramel Association (ITCA) classifies caramel colors according to four general "Classes", based upon whether ammonia and/or sulfite are employed in their preparation (and the nitrogen and sulfur content resulting therefrom) and ten specific "Types" based upon their color intensity, as shown in Table I.
The coloring properties of caramel colors are substantially attributable to the presence therein of high molecular weight materials commonly referred to as "color bodies". Caramel colors also contain a variety of low molecular weight materials which are largely devoid of any particular beneficial function with respect to the coloring properties of caramel colors but may contribute to some degree to the flavor, stability and foaming properties of caramel colors.
TABLE 1 __________________________________________________________________________ CLASSIFICATION OF CARAMEL COLORS (PROPOSED) __________________________________________________________________________ Class No. I II III IV Class Name Caramel Color, Plain Caramel Color, Caramel Color, Caramel Color, Caustic sulfite process Ammonia process Sulfite ammonia process Class Code CP CCS AC SAC Use of ammonia - - + + Use of sulfite - + - + Total N, % &lt;0.1 &lt;0.1 .gtoreq.0.1 .gtoreq.0.1 Total S, % &lt;0.1 .gtoreq.0.1 &lt;0.3 .gtoreq.0.3 Type CP-1 CP-2 CCS AC-1 AC-2 AC-3 SAC-1 SAC-2 SAC-3 SAC-4 Color Intensity* 5-35 40-80 40-80 60-90 100-140 150-200 35-70 75-100 105-150 210-270 __________________________________________________________________________ *of an 0.1% w/v solution at 610 nm in a 10 mm cell
The prior art evidences attempts to treat caramel color to separate its color-contributing materials from its non-colorant materials and thereby obtain a concentrated product which, in addition to its decreased weight and volume, possesses increased coloring or "tinctorial" power, i.e., as compared to untreated caramel colors, less caramel color concentrate need be utilized to obtain a particular level or intensity of color in a product. The methods proposed for this purpose seek, in particular, to isolate the color bodies from caramel colors. Thus, for example, U.S. Pat. Nos. 2,533,221; 2,637,655 and 2,902,393 describe processes wherein coagulating and precipitating agents are added to caramel colors to isolate caramel color concentrates high in color bodies; U.S. Pat. No. 2,701,768 discloses a process utilizing dialysis to remove non-color materials from caramel color; and U.S. Pat. No. 3,249,444 discloses a process utilizing ultrafiltration to separate the color bodies of caramel colors from non-color materials.
Each of the described processes exhibits its own particular disadvantages in the context of the desired objective, i.e., in producing caramel colors of increased coloring power. For example, some recommended treatments are difficult to practice on a practical, commercial scale involving significant quantities of materials and rapid throughputs through required equipment and operations. More importantly, however, the products of these processes, although containing concentrated amounts of colorant materials, do not necessarily retain the desirable properties present in the parent caramel color.